Underreaming tool



Feb. 2,. 1932.

F. C. FARMER UNDERREEAMING TOOL Filed Feb. 24, 1950 IN VENTOR Ewan: ai'drmer BY I 7 ATTORNEK il l HQ ll lkk ll lhl P H Patented Feb. 2, 19321 NIT D STATES FRANCIS o. rARMEn, or LOS enemas, CALIFORNIA, ASSIGNQR TO far 'r oFF CE- JOHN GRANT, or

LosrmeELns, CALIFORNIA.

UNDERREAM1NG moon Application filed February 24, '1930. Serial No. 430,752.

. provide atool of the character stated which will be an improvement upon others of its class with respect to efliciency and dependability of operation; one .inwhich the cutting elements may bemore readily and conveniently inserted andremoved after they have become worn in order that new cutting I elements may be inserted and a general construction which improves upon the prior devices of the class with respect to variousother details, all of 'which will hereinafter more-fully appear.

Referring in detail to the accompanying drawings which illustrate what is at present deemed to" be a preferred embodiment of the invention,

- Fig. 1 is'a side elevation of the complete tool'mou'nted in position for use, a portion of the View being shown in mid-section.

Fig. 2 is a sectional detailshowing one of the cutting elements in a different position from that wherein it is shown in Fig. 1.

F ig. 3 is across section on line 3' 3 of Fig. l.

' Fig. 4 is a cross section on line 4- 1- of Fig. 1.

Fig. 5 is a fragmentalsectional detail of the releasing device to permit removal ofthe rotary cutter, on line '5.5 of Fig. 6.

F ig. 6 is a fragmental view of a part of Fig. 1, and also may be regarded as a section on line 6-6 of Fig. 5. p

Fig. 7 is a cross section on line 7-7 of Referring in detail to the drawings, th tool is provided with a cylindrical body portion 10 having a shank 11 which is united thereto by a tapered 'portionf12 whereby the tool maybe attached to the usual tool joint 13. The bodyportion of the tool is formed in two sections, a mainupper section 10 and a lower section 20, these sections being longitudinally movable with relation toeach other and'having between them a broad circumferagainst theend of said pin.

ifential recess or groove which provides space for in serting the rotary cutters 21, two

or more of said cutters being usually employed. vVithin said groove 201" the body 10 is provided with a diametrically reduced cylindrical extension 23'whereby the portion 10 of the tool is unitedlto the lower portion 20 thereof. Through said stem 23 extends an axial water supply passage 25, said passage continuing the entire length of the tool. At the lower end of the tool a fish-tail'bit 26'is shown attached by a' conventional screwthreadedshank 27 or other drilling means.

The invention resides more particularly in the links30 and the parts which cooperate with them, whereby the upper end portions of the cylindrical cutters21 are e'xpansibly attached in the operative position to underream the sides of the well bore below the lower end of the well casingC.

Each of said links 30 is mountedto swing through a vertical plane in a recess in the toolbody 10, and is pivotally attached at its inner end by means of a horizontally extend- 7 ing pin 36 which is inserted into asuitable links 30 are preferably rounded as shown.

Each of the pivot pins 36 for'attaching the links 30 fits into a hole 36h, indicated in dotted lines in Fig. 2, said hole being bored in the direction of a chord with respect to the cylindrical body of the tool, but not being drilled quite through the tool, there being a diametricallyreduced hole 36z' which leads from the base of hole 36 to the adjacent side of the tool. The pin 36 is driven tightly into the hole 36a so that it will not be accidently displaced. When it is desired to remove the pin 36, nail or suitable tool is inserted through the hole 3671 and is then driven Each cylindrical cutter 21 is rotatably i'nounted upon a shaft 38 whi'ch'is of greater lengtlrthan the cutter so that each endof said'shaft projects beyond the adjacent end of the cutter. The upper end of said shaft is provided with a transversely flattened head hole provided therefor. The end portions of 39 whicln occupie's a slot 40 cut into the outer end of the-"link, and by means of a pin '41 is pivotally connected with said link;

Each link 30 is mounted to swing from a somewhat inclined position, shown in Fig. 2, to a substantially horizontal position as shown in Fig. 1, the upward movement of said link being limited by a shoulder 3564 at the upper end of recess 35. The rotary cutter elementsare by preferenceand as shown, formed in two parts, namely; the main cylindrical cutter 21, and the small auxiliary :frustro-coni'cal cutter 210/ which is seated upon the upper end thereof. The lower'end of each cutter 21 is preferably beveled at 21?).

The lower sleeve section of the tool is operatively secured to the hexagonal stem part 238 by means of 'a set screw 60 having a {shank-61 at its inner end which cooperates with a groove 62 formedtmone face of said hexagonal stem. Sa1d groove 62co1npr1ses a lowerend portion or recess 63 which issepa- .rated from the upper portion of the groove "by means of a shoulder or r1se-6 i-of less heightthan the depth of the-groove as well shown-in 5. This construction makes it possibleto allowthe shank portion 61 of'the :screw,60.to formafkey which pcrmits'a longitudinal but nonrotatable movement between the sleeve ,part 20 and the stem 23 when said :screw. shank 61 is, brought into register with said recess621and screweddown ,theremto. =If-thescrew-1s screwed-down far enough to project beyond the-outer surface of the sh0ulder:or rlse 64.,sa1d rise Wlll act as a stop to limit the downward movement of the screw.

The compression spring- 51acts-between the shoulder-51s and the nut 50.

, Assuming .the screw to be inserted to the extent {and in the position just v mentioned, if it is desired .to remove one or more of the cylindrical cutters .31, .the screw :61 .is unscrewed a sufiicient distance to permit it to be moved across the rise 64 and brought into register with the recess 63. Under the condition just described the lower section or body 20.0f the tool may be extended from thetremainder of vthe tool against the opposition of spring .51 a sufficient (distance to permit the 'lowerendsof the shafts 88 to be swung out of their seats 45 whereupon the cutters Bland 31a may beslid oil from the shafts..3d perrnitting =worn cutters to be replaced ,by new .ones. I

Inorder-to prevent the screw 60 from unserewinglso far as tc-entirely withdraw itself into which said screw ,is inserted is preferably peenedover at .690.

The axial water supply passage which from .tl1egroove 62, the outer end of the bore extends"from end .to end of the too-his -.pro-

yided .with radial ports or passages 250, one ,of which s shown in Fig. 1', which open out adJacent to the upper ends of the cylindricai @cutters 1-31 to eificientlvsup-ply a cleansing stream of waterito these cu-tters during their operat1on-.'- I I .of the stem.

of "the link that-whenthelink swings up into contact with the shoulder the link will then have passed a little above the horizontal dead center line along which pressure is. applied theretoduring theoperation of the cylindrical c'utter 21. This construction causes the pressure. during operation ofthecuttersito be received by the curved bearing surface 356 instead of by the pivot -pin136,thuspreventinglthe pin from beingbroken (and insuring efiicient service. 7 r v p v Also the lower end parts .of' each of the cutters 31 of the stem 23 is ,preferably'providedon its adjacent face with a scalloped outer or recessed'portwn 23m to :prov1de additional clearance between the cutter 31 and the stem 23 so that;gritty-substances will not be apt to become impacted between the lower portion of the cutter and the adjacent part This recess allows the water to more freely circulatearound the lower portion of the cutters to'keepthem clean.

lnoperation while-thetoolis being'lowercd into the casing of a well in which it is-desired to per-formwan un derreaming operation below the lower end of thewell-casrngQ-each o-f-the links will drop to :the inclined position shown in Fig. 2 thus permitting the-upper -endsoftherespective cutters 31 -t0=SWlI 1g'SL11'll :cien-tly inward to 1 clear the. inner wall .of the casing Gduringthe descent-ofrthetool; This inward swing of the links 30 is permitted by reason ofthe weight of the relatrvely'heavy sleeve section 20.'overcom1ng@the opposition of spring $51 and causing the upper end of the sleeve section 20 to withdraw from the shoulder 208 thus permittingthe cutter. shafts 38 together with the links 30 to which they are pivoted-to fall to the position shown in 'Fi 2.

Wh en thedrill 26 encounters the bottom of I the well, the weightofthe upper shankmem- .ber lO-and-the parts ilhQIGEtlJOVQ/'lVllliCfillSG the upper and lower sections of .t'he -tjool to approach each otheruntil the upper end ofthe lower section 20 again engages the shoulder 20s of the-stem,'thus forcingthe upper ends of the shafts 38--together-with the cutters 31 and 31a mounted thereupon, into the operating or underreaming position shown in Fig. 1. sockets l5 in which are'seated the lower ends of the shafts 38 will beef sufficient'diameter to permit the swinging movement to occur between the -positions of said shafts shown in -F i-gs. 1 and 2. Saidsockets act-as- It is to be understood thatwthe shaft therein, aswingable link with which guides which keep the cutters in place during the swinging movement of the links 30.

Although I have shown anddescribed what is at present deemed to be a preferred embodiment of the invention, yetit is to be understood that various changes, such as come within the scopeof the appended claims, may be made in the construction disclosed without departing from the spirit of the invention.

The upper end of each of the shafts 38, upon which'the cutters 21and 21a are mounted, is provided with a collar 450 preferably integral therewith which prevents excess upward movement of the cutter 21a and also guides both of the cutters on each shaft effectively toward their cutting position.

Claims: r

1. An underreaming tool comprising an elongated body adapted to Y be lowered through a well casing, said body being formed in two sections which normally have a limited longitudinal movement with relation to each other, a shaft extending length-' wise of said body, one end of said shaft being seated in a recess provided in one of said body sections, said recess being of sufiicient diameter to permit a tilting movement of said the opposite end of said-shaft is connected, and a cylindrical cutter mounted upon said shaft, said link shaft and body sections being so related to each other that a movement of the body sections toward each other will cause said link to swing said shaft and cutter out from an inoperative position to an underreaming position.

2. An underreaming tool comprising an elongated body adapted to be lowered through a well casing, said body consisting of two sections which normally have a limited longitudinal movement with relation to each other, a shaft extending length-wise of said body, one end of said shaft being seated in a recess provided in one end portion of one of said body sections, the end portion of said shaft which is seated in said recess extending thereinto a sufficient distance to prevent withdrawal thereof from said recess during. the .normal relative longitudinal movement of said body sections, stop means to arrest said body, one end of said shaft being seated in a seat provided by one of said body sections and the other end of said shaft being pivotally connected with the other of said body sections, and stop means normally to limit the movement of said body sections away from each other, said stop means being adjustable to permit the movement of said body sections away from each other to be increased beyond the normal for the purpose of freeing'said shaft from said seat, and a rotary cutter mounted upon-said shaft and removable therefrom when the latter is freed from its seat.

. 4. An underreaming tool comprising an wise of said body, one end of said shaft being seated in a guide provided in one of said body sections, a swingable link with which the opposite end of said shaft is connected, and

a cutter mounted upon said shaft when said cutter is in its most retractedposition, said link being outwardly inclined with relation .to the axis of said body sections so that a movement of the body sections towards each other will cause said link to swin said shaft and cutter out from an inoperative position to an underreaming position. v

In testimony whereof I hereunto affix my signature. FRANCIS C. FARMER,

the movementsv of saidbody sections away of two sections which normally have a limited longitudinal movement with relation to I each other, a shaft extending-lengthwise of 

